The Method Of Inversion Parameters Of Media Using Observed Ground Penetrating Radar

From Maxwell's equation we derive formulas for inversion of permittivity and conductivity of media using observed ground-penetrating radar. By introducing an adjoint field calculated using Maxwell's equation, the gradients of the objective function with respect to unknown parameters can be expressed explicitly. The procedure of inversion is: first of all, to build up initial model and to calculate guessed data using this model. Secondly using the waveform inversion formulas to calculate adjoint fields, thirdly to calculate gradients and to modify the model. These steps are repeated until an acceptable result is obtained. In the modification of model, the conjugate gradient method is used. In latter half of the paper, writer gives some different kinds of examples, such as the inversions from noise-free and noisy data with different signal-to-noise ratio, two objects, layered media, etc. By comparing the reconstructed models with actual ones, we know that they are coincident.